My issue now is that I have 4 bettas. One will be in the 40 gallon. I have two 4 gallon i keep on my desk with a betta each, but i need another community tank for a betta. So now i have to figure out what to put with a 10 gallon with my forth betta. Some tetra or rasbora that feeds from the surface

aye. i have four bettas. three dont care about shrimp, but the most well rounded and female one, she is a hunter. I saw her kill my golden yellow shrimp right in front of me. She doesn't have any stand out qualities except being well rounded and not quirky, and also being a hunter